FARADAY ROTATION MEASURE SYNTHESIS OF INTERMEDIATE REDSHIFT QUASARS AS A PROBE OF INTERVENING MATTER
FARADAY ROTATION MEASURE SYNTHESIS OF INTERMEDIATE REDSHIFT QUASARS AS A PROBE OF INTERVENING MATTER
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DOI：
10.3847/0004-637x/829/2/133
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发表时间：
2016-03
期刊：
影响因子：
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通讯作者：
Kwang Seong Kim;S. Lilly;F. Miniati;M. Bernet;R. Beck;S. O’Sullivan;B. Gaensler
中科院分区：
文献类型：
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作者：
Kwang Seong Kim;S. Lilly;F. Miniati;M. Bernet;R. Beck;S. O’Sullivan;B. Gaensler
有证据表明，在背景源的偏振特性中，可以检测到沿着遥远类星体视线的磁化材料。偏振特性似乎与存在的干预镁ii吸收，这被认为是出现在流出的物质从星星形成星系。为了进一步研究这一点，我们已经获得了高光谱分辨率的偏振测量，与甚大阵列和澳大利亚望远镜紧凑阵列，一组49个未解决的类星体，我们有高质量的光谱。这些使我们能够产生一个法拉第深度光谱的每个来源，使用旋转测量（RM）合成。我们新的独立无线电数据证实，干预者与去极化密切相关。我们的特点的复杂性的法拉第深度光谱使用的一些参数，并显示这些是如何相关的，或不，去极化和存在的镁II吸收沿着视线。我们认为，复杂性和结构的法拉第深度分布可能会出现从两个干预材料和内在的背景源，并试图将这些分离。我们发现，在红移处与介入物质相关的强射电去极化效应是由不均匀的法拉第屏引起的，它在各个源之间产生了大约10 rad m−2的RM色散。这可能是由强度至少为3 μG的无序场产生的。
There is evidence that magnetized material along the line of sight to distant quasars is detectable in the polarization properties of the background sources. The polarization properties appear to be correlated with the presence of intervening Mg ii absorption, which is thought to arise in outflowing material from star forming galaxies. In order to investigate this further, we have obtained high spectral resolution polarization measurements, with the Very Large Array and the Australia Telescope Compact Array, of a set of 49 unresolved quasars for which we have high quality optical spectra. These enable us to produce a Faraday Depth spectrum for each source, using Rotation Measure (RM) Synthesis. Our new independent radio data confirms that interveners are strongly associated with depolarization. We characterize the complexity of the Faraday Depth spectrum using a number of parameters and show how these are related, or not, to the depolarization and to the presence of Mg ii absorption along the line of sight. We argue that complexity and structure in the Faraday Depth distribution likely arise from both intervening material and intrinsically to the background source and attempt to separate these. We find that the strong radio depolarization effects associated with intervening material at redshifts out to arise from inhomogeneous Faraday screens producing a dispersion in RM across individual sources of around 10 rad m−2. This is likely produced by disordered fields with strengths of at least 3 μG.